The purpose of this study was to understand high-risk young adults' use of the rapid human immunodeficiency virus (HIV) self-test. The highest rate of new HIV infections occurs in people between 15 and 24years. Improving identification of young people infected with HIV is a critical public health priority. The first rapid HIV self-testing kit was approved in the US in 2012. Despite the product's promise, its use by untrained young adults is not well-understood. We conducted a mixed methods study using surveys, a think-aloud protocol, observations, and in-depth interviews. A systematic checklist was developed to assess participants' use of the test. A total of 21 racial and/or ethnic minority young adults aged 18-24 participated in this study. Analysis of our interview data was guided by the theory of reasoned action (TRA). Participants completed the initial procedures of the test with a mean time of 8:36min (range of 2:04'-16:33'). On a 14-point checklist, participants had a mean score of 10.8 (SD 2.26, range 3-14). In the qualitative analysis of the participants' interviews, guided by the theoretical constructs of the TRA, the following themes emerged: "Did I use it correctly?", "Can I trust the results?" (attitude); "How will my partner react?!", "What will people think?" (subjective norm); "Quick, easy and blood free," and "Avoids the hassle of dealing with the healthcare system" (behavioral intention). This study provided evidence of the usefulness of the test perceived by young adults, especially in light of their concerns about lack of privacy in medical settings. Since many participants did not follow all of the instructions while using the test, it is not evident that young adults can correctly use the HIV self-test. Development of instructions manuals that are understandable and guide proper use of medical devices is a great need, especially in the context of home testing technology.